Normal distibution.

A pizza place offers 3 different cheeses and 12 different toppings. In how many ways can a pizza be made with 1 cheese and 3 toppings?
A.198
B.660
C.1485
D.2376

The time required to finish a test in normally distributed with a mean of 40 minutes and a standard deviation of 8 minutes. What is the probability that a student chosen at random will finish the test in more than 56 minutes?
A.84%
B.2%
C.34%
D.16%

What percentage of the data falls within 1 standard deviation of the mean?
A.68%
B.95%
C.99%
D.100%

A pizza place offers 3 different cheeses and 12 different toppings. In how many ways can a pizza be made with 1 cheese and 3 toppings?
A.198
B.660
C.1485
D.2376

Consider and

Originally Posted by Taylo17

The time required to finish a test in normally distributed with a mean of 40 minutes and a standard deviation of 8 minutes. What is the probability that a student chosen at random will finish the test in more than 56 minutes?
A.84%
B.2%
C.34%
D.16%

What do you get?

Now find

where 'a' is the result you found.

Originally Posted by Taylo17

What percentage of the data falls within 1 standard deviation of the mean?
A.68%
B.95%
C.99%
D.100%

There is no working to be done here, this is information your text book should provide.